reCaptcha V2 Server

This code is to be deployed to a Heroku app. The frontend form will then send the captcha data to the Heroku app and wait for a success response before submitting the form.

Instructions

1. Register your site/ get your reCaptcha keys here
2. Create a new Heroku App
3. In your new Heroku App, go to settings and create a new Config Var called RECAPTCHA_SECRET and enter your secret key in the value field
4. Deploy this code to your Heroku app via the Heroku CLI or hook up the GitHub repository via the Deploy tab in your Heroku App
5. After you deploy your app, your app url should display 'reCaptcha verification'

Frontend Instructions

1. Add captcha script tag <script src="https://www.google.com/recaptcha/api.js" async defer></script>
2. Add captcha element to form <div class="g-recaptcha" data-sitekey="YOUR_RECAPTCHA_PUBLIC_SITE_KEY_HERE"></div>
3. Add form event listener to send reCaptca data to Heroku server:

var form = document.querySelector('#contact-form');

form.addEventListener("submit", function(event) {
    event.preventDefault();
    event.stopPropagation();

    var recaptcha = document.querySelector('#g-recaptcha-response').value;

    fetch('HEROKU_APP_URL_HERE', {
        method:'POST',
        headers: {
            'Accept': 'application/json, text/plain, */*',
            'Content-type':'application/json'
        },
        body:JSON.stringify({captcha: recaptcha})
    })
    .then((res) => res.json())
    .then((data) => {
        console.log(data);
        if(data.success) {
            // Submit form if success status returned
            form.submit();
        } else {
            // Handle error messages            
        }
    });
}, false);